2017/07/17 by I. Oteo, Oteo, I., I. Smail +30
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #astro-ph.GA
paper · pdf · doi:10.48550/arxiv.1707.05329
Submitted to ApJ. Comments welcome
arxiv created 2017/07/17 · openalex publication_date 2017/07/17 · arxiv updated 2017/07/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We have combined the wide-area Herschel-ATLAS far-IR survey with spectroscopic redshifts from GAMA and SDSS to define a sample of 21 low--redshift (z\rm spec < 0.5) analogs of submm galaxies (SMGs). These have been selected because their dust temperatures and total IR luminosities are similar to those for the classical high-redshift SMG population. As well as presenting the sample, in this paper we report 12CO(2-1) and 12CO(1-0) observations of 16 low-redshift analogs of SMGs taken with the IRAM-30m telescope. We have obtained that low-redshift analogs of SMGs represent a very diverse population, similar to what has been found for high-redshift SMGs. A large variety in the molecular gas excitation or 12CO(2-1)/12CO(1-0) line ratio is seen, meaning that extrapolations from J ≥ 2 CO lines can result in very uncertain molecular gas mass determinations. Our sources with 12CO(1-0) detections follow the dust--gas correlation found in previous work at different redshifts and luminosities. The molecular gas mass of low-redshift SMGs has an average value of M\rm H2 ∼ 1.6 × 1010 M_\odot and will be consumed in ∼ 100 \rm Myr . We also find a wide range of molecular gas fractions, with the highest values being compatible with those found in high-redshift SMGs with 12CO(1-0) detections, which are only the most luminous. Low-redshift SMGs offer a unique opportunity to study the properties of extreme star formation in a detail not possible at higher redshifts.